Tools are utilized by many different crafts persons for working on various types of materials to fabricate an object with the desired shape or form. While the majority of tools are utilized by machinists and other crafts persons working in similar trades, various types of tools are also utilized on a daily basis by artists, carpenters, cabinet makers, engineers, physicians, dentists, etc. Depending on the application to which the tool is applied, the particular devices may be moved by hand, rotated, reciprocated or otherwise vibrated to operate upon the surface of the workpiece.
In many applications, there is a need to smooth an otherwise rough workpiece surface. Hand files, sanders, shapers, planers, etc., are well adapted for creating a smooth workpiece surface. While these and other tools are well adapted for carrying out this function, the operation of such type of tools requires a certain degree of skill to prevent an excessive amount of material from being removed from the workpiece to prepare a smooth surface. In other words, in utilizing many of these smoothing-type tools, the operator must be careful to halt the operation once the surface is smooth, otherwise, the continued operation of the equipment will only unnecessarily remove further material from the workpiece.
In the dental field, doctors routinely utilize ultrasonic scalers to remove brittle calculus, tartar, altered cementum and other accumulated residue from a patient's tooth. During supragingival scaling or root planing, the material to be removed is universally rough with multiple jagged and protruding edges. The buildup on the enamel of a tooth is undesirable which, if not removed, can be damaging to the tooth and gingival tissue. The ultrasonic scaler is equipped with a tip which mechanically vibrates at a high frequency. When brought into contact with the hardened residue, the brittle material is fractured and eroded and removed from the tooth. The end of the metal tip of the ultrasonic scaler insert fractures and breaks the brittle buildup with a micro-hammer action. This method of removing calculus from a patient's tooth is well documented in the dental literature. In order to facilitate the removal of calculus and other materials formed over time on a patient's tooth, the ultrasonic tip can be coated with diamond particles, such as disclosed in U.S. Pat. No. 4,731,019 by Martin. The diamond particles covering the ultrasonic scaler tip function to accelerate the abrasion of the brittle calculus. Indeed, an extreme amount of care must be exercised by the doctor in the utilization of this tool, otherwise, the surface of the tooth will be abraded and damaged. It can be appreciated that the doctor or assistant must be very attentive when utilizing this ultrasonic tool, otherwise, the tooth, bone or other hard surface will be damaged beyond repair. It will also be appreciated that when the tip of this tool is utilized on that part of the tooth in the gingival pocket, excessive tooth abrasion can occur because the surgeon is unable to visually observe the tooth surface being operated upon. As a result, diamond coated ultrasonic tips have been limited to a small specialty area of dentistry by experienced doctors, namely, the periodontal surgical area.
Ultrasonic operated devices utilize tips that are constructed of specified lengths so as to be tuned. A tuned tip provides optimum magnitude vibrations and thus is effective to micro-hammer object surfaces. Standard ultrasonic tips are effective only along about 4-6 mm at the end of the tip to remove accretions on a tooth surface. The other portion of the ultrasonic tip is less effective as an instrument to remove calculus and tartar buildup on tooth surfaces.
It is well known in the art to bond diamond particles to tool bits, and the like, in order to accelerate abrasion of the workpiece and extend the life of the tool. Diamond whetstones are such type of tools. These tools are fabricated by bonding a diamond abrasive in raised islands on the surface of the tool. The raised islands of diamond particles are effective to erode the surface of the workpiece. Again, the surface of the workpiece continues to be eroded as long as the operator moves the whetstone over the surface of the workpiece.
As noted above, ultrasonic scaler tips that are covered with a diamond abrasive grit currently exist. Abrasive or sharp edges on the surface of a scaler tip have been shown to be an effective means of removing tartar and roughness from the tooth surface. However, studies have demonstrated that abrasive areas and sharp edges, when vibrated by an ultrasonic scaler and placed directly against the tooth surface, will damage the surfaces of the tooth and root. In other words, not only the calculus, tartar, and other unwanted rough surfaces will be removed as desired, but a significant portion of the tooth surface will also be removed, thus causing permanent damage to the tooth.
From the foregoing, it can be seen that a need exists for a tool that removes roughened areas of a workpiece surface, but once a smooth surface is achieved, further erosion of the surface does not occur, even if the tool continues to be moved over the work surface. Another need exists for a tool that can be used by a technician to smooth surfaces of workpieces without utilizing a high degree of skill. Another need exists for an ultrasonic tip which, when used on tooth surface that cannot be easily observed, does not continue to erode the surface of a tooth once a smooth surface is achieved.